The present invention relates to a temperature control unit for dies or molds particularly for pressure die-casting or injection-molding aluminum and alloys thereof, plastic materials and the like.
It is known that the temperature control of dies or molds, particularly for die-casting aluminum and alloys thereof, currently uses oil-based devices which substantially have a closed circuit for the oil which is designed to perform heat exchange with the die or mold.
The use of oil entails the provision of a heat exchange unit for cooling the oil; such cooling occurs indirectly by transmission of the heat from the oil to the cooling water.
With systems of this type, therefore, it is necessary to have a large mass of circulating oil, with consequent operating costs and with the need to periodically replace the oil, with oil disposal costs.
Another problem further consists in that due to the high heat capacity it is necessary to supply large amounts of energy for the initial step of oil preheating, with consequent high operating costs.
The aim of the present invention is to solve the above problem, by providing a temperature control unit for dies or molds particularly for pressure die-casting aluminum and alloys thereof which can use water as a heat exchange fluid, with consequent significant savings on installation and operating costs, since there are no disposal problems; moreover, water has a much higher heat exchange rate than oil.
Within the scope of this aim, a particular object of the present invention is to provide a temperature control unit which allows to significantly reduce the thermal shock to the molds or dies, achieving gradual temperature variations, even during cooling, with the possibility to reach very low levels for the temperature of the dies or molds, thus facilitating extraction of the part from the mold or die.
Another object of the present invention is to provide a temperature control unit for molds or dies which by way of its particular constructive characteristics is capable of giving the greatest assurances of reliability and safety in use.
Another object of the present invention is to provide a temperature control unit which can be easily obtained starting from commonly commercially available elements and materials and is also competitive from a merely economical point of view.
This aim, these objects and others which will become apparent hereinafter are achieved by a temperature control unit for dies and molds, particularly for pressure die-casting or injection-molding of aluminum and alloys thereof, plastic materials and the like, characterized in that it comprises a die or mold cooling circuit through which pressurized water flows, a water feed pump being connected to said circuit and being adjustable to a pressure which is higher than the evaporation pressure of water at a preheating temperature of said water, which can be detected by a first sensor for detecting the temperature of said water, said circuit including a circulation pump, a water overflow valve which can be set to a lower pressure than said feed pump, and a heating unit which is controlled by said first temperature sensor, a die or mold temperature sensor being further provided which controls said feed pump.